This invention relates to a safety system for power-take-off, and in particular to a safety device that automatically shuts off the power-take-off in an emergency.
Tractors are usually provided with a power-take-off so that the power of the tractor can be used to drive various pieces of machinery, for example augers and grinders. The machine is connected to the power-take-off of the tractor with a power-take-off shaft. The controls for the power-take-off are all on the tractor, and should an emergency arise, often the only way to turn off the machine is by turning off the power-take-off on the tractor. However, the tractor controls are often left unattended while the implement is being used, particularly on a small farm. There have been several reported instances where the operator has become entangled with the machine or the power-take-off shaft, and sustained serious injuries because he or she could not reach the controls to turn off the power-take-off. These injuries have been compounded by the delay in assistance, because it was not readily apparent to passers-by that anything was amiss.
The safety system of the present invention is adapted for use with a machine that is being driven by the power-take-off of a tractor. Generally, the system comprises at least one sensor for detecting the presence of a foreign body adjacent the machine and/or the power-take-off shaft. A shut-off, responsive to the sensor, automatically shuts off the power-take-off when the sensor detects the presence of a foreign body. The system may optionally be provided with an alarm that is activated when the power-take-off is shut off, to summon assistance. Thus, when a person, animal, or object approaches selected portions of the machine and/or the power-take-off shaft, the sensors detect its presence, and the power-take-off is shut off. The sensors are preferably positioned to shut off the power-take-off before any serious injury has occurred. The sensors must be positioned, however, to allow proper functioning of the machine without unnecessary interference.
The safety system is of simple and relatively inexpensive construction. The system can be easily retrofit to existing tractors and machines, as well as be provided on new equipment. The sensors can be positioned about the machine and the tractor so as not to interfere with the normal operation of the equipment, and are preferably only activated when the power-take-off is being used. The sensors preferably anticipate potential injuries by detecting the presence of foreign objects where they should not be, and shutting off the power-take-off, to prevent the machine from causing injury to persons or animals, and damage to property. An automatic alarm can be provided to promptly summon help, in the event the operator is unable to do so, or is not present.
These and other features and advantages will be in part apparent, and in part pointed out hereinafter.